Double-throw bolt



S. W. PARSONS.

DOUBLE THROW BOLT.

APPLICATION FILED JAN. 5,1911.

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2 SHEETS-SHEET I.

Patented Mar. 23, 1920.

S. W. PARSONS.

DOUBLE THROW BOLT.

APPLICATION FILED JAN-5,1917.

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UNITED STATES PATENT orrron.

STUART W. PARSONS, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE STANLEY WORKS, OF NEW BRITAIN, CONNECTICUT, A. CORPORATION CIT-CONNECTICUT.

DOUBLE-renew BOLT.

Application filed January 5, 1917.

To all whom it may concern Be it known that I, STUART W. Parsons, a citizen oi? the United States, and a resident of New Britain, inthe county of Hart ford, State of Connecticut, have invented certain new and useful Improvements in Double-Throw Bolts, of which the following is a specification.

The structure with which this invention is concerned is commonly known in the hardware and building trades as a Cremone bolt. It is adapted to be secured to the inner face of a door, havingan upwardly projecting bolt for engagement with the top off the door frame and a downwardly projecting bolt for engagement with the still, the two bolts being simultaneously oper ated by a single handle positioned between the inner ends of the bolts. The present invention provides a new and useful operating mechanism for the bolts, an adjustable connection between the bolts and the operating mechanism, and various other features of improvement which will be more particularly set forth in the following description and claims. For convenience in (lBSClllliIlg the invention the structure will be referred to as a Gremone bolt.

Referring to the drawings Figure l is a view of such a bolt in eleration.

Fig. 2 is a view with the operating case removed, showing one extreme position, the bolts being broken 013:.

Fig. 3 is a view similar to Fig. 2 but with the bolts in the opposite extreme position.

Fig. 4: is a detail view showing the rela tive position of the operating mechanism when the bolts have been moved to an extreme position and before the operating member has been moved to locking position.

.Fig. 5 isa sectional view on the line 5--5 of Fig. 3, but showing only the actuating and connecting portions of the device.

In the drawings, A, B, denote the upper and lower lock bolts respectively. The various parts indicated by C denote the straps secured to the door 'for the guidance of the bolt. D is a back plate secured to the door, and to which the operating case E is secured.

The operating mechanism comprises a pair of oppositely arranged racks, 5, 5, evenly spaced on opposite sides of the pin Specification of Letters Patent.

Patented Mar. 23, 1920.

Serial No. 140,727.

ion 6 which is secured on a short stub shaft 7, the inner end of which has a hearing at 8 in the back plate, the front end of which projects through and has" a bearing in the operating case and has secured to it a handle 10. The shanks 15, 15, of these racks are in alinement and carry studs 16, 16, which are adapted to fit into one of a series of apertures 17 in the ends of the bolts A, B, in order that the length of the bolts may be adjusted to suit the requirement oi any given case. T he operating case is secured to the back plate, and as will be evident the connections between the bolts and the rack shanks are concealed, thus making it impossible to tamper with the adjustment of the bolts.

It will be seen from an examination of the racks and pinion that the raclrs have a. large central tooth meshing directly with the pinion teeth, and at either end a small or narrower tooth. By this arrangement the pinion moves the lSChIFl, and consequently the bolts, to either one of their extreme positions, and then the pinion is capable of a ier movement independent oi the racks, up; a tooth oi: the pinion into an abutting]; position relative to the rack and particularly to the large central tooth thereof, with the result that this direct abutment between these parts constitutes a positive locking, preventing any movement of the belts or the pinion in an improper manner, as by prying under the ends of the bolts to force them back.

Building hardware, and especially the devices included herein and forming the subject matter of this case, are of such a char actor that nicety and precision in manufacture are not desired, and in order to avoid the requirement for great care in manufacture parts composing my improved device, and especially the engaging and locking teeth between. the pinion. and racks, are iormed so that considerable permissive rotative movement is allowed for the pinion while maintaining it in locked engagement with the rack. This not only removes cause for great care in manufacture but also allows for much wear between the parts with out causing them to become inoperative. In eli'ecting this result the teeth on the pinion, and especially the teeth engaging the teeth on the rack at the time said parts are in locked engagement, has a wide crown conthe invention "can be carried out stituting a locking surface that engages with a tooth on the rack during rotation of the pinion to a considerable degree, so that after the parts have reached their locked position the pinion may yet-bel'noved to a considerable extent without disturbing the locked condition-of the members.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now considerto represent the best embodiment thereof; but I desire to have it understood that the apparatus-shown is only illustrative, and that by other means.

pair of-oppositely arranged racks eachharing a large tooth and a narrow tooth at each side of the large tooth, and a pinion between said racks provided w1th teeth each having-a relatively large crown and adapted to engage the teeth on said racks, the crown portions of diametrically opposite teeth on said pinion having a slidable and locking engagement with the large tooth on said "racks so that when the racks are in extreme position the pinion is rotatable independently of said racks.

STUART V. PARSONS. 

